Matthew P. Foley

Process variables that control natural fiber welding: time, temperature, and amount of ionic liquid

A systematic study of variables that affect the fiber welding process is presented. Cotton cloth samples are treated with controlled amounts of 1-ethyl-3-methylimidazolium acetate for a series of times and temperatures. Diluting the ionic liquid with a volatile molecular co-solvent allows temporal and spatial control of the welding process not possible with neat ionic liquids. Materials are characterized by scanning electron microscopy, infrared spectroscopy, X-ray diffraction, and mechanical (tensile) testing. Results suggest careful management of process variables permits controlled, reproducible manipulation of chemical and physical properties.

Fluorescence monitoring of ionic liquid-facilitated biopolymer mobilization and reorganization.

Ionic liquid-facilitated mobilization and reorganization of biopolymers in natural fibrous materials is visualized by confocal fluorescent spectromicroscopy. Ionic liquid-based processes controllably fuse adjacent fibres while simultaneously leaving selected amounts of biopolymers in their native states. These processes generate congealed materials with extended intermolecular hydrogen bonding networks and enhanced properties.

Characterization of Polymer Movement in Fiber Welded Cellulose Composites

Ionic liquids are effective solvents for the dissolution of biopolymers such as cellulose and silk. New materials can be created from these natural feedstocks by processes that involve the full dissolution of biomaterials. Many reports show that the dissolution and reconstitution processes eliminate the native polymer structure, often with deleterious consequences to the physical properties of the material. Recently, it has been shown that robust biopolymer based structures may be created without full dissolution of the material by a method we call “Natural Fiber Welding”. The welding process generates modified natural fiber structures while leaving much of the material in its native state. As a result, natural fiber welding enables tunable preservation of native microstructure while also affording manipulation of important material properties.

Phase Behavior and Solvation of Lithium Triflate γ-Butyrlactone

Data describing the concentration and temperature dependent solvation and phase behavior of lithium trifluoromethanesulfonate (LiTf) in γ-butyrolactone (GBL) is presented. Differential scanning calorimetry (DSC), Raman spectroscopy and X-ray diffraction measurements are employed to elucidate the electrolyte interactions. DSC analysis show the presence of a crystallinity gap at concentrations between 2.56:1 and 5.00:1 GBL:LiTf (mole:mole) and a high melting solvate in more concentrated samples. Raman spectroscopic analysis indicates that the coordination of ions in the high melting solvate undergoes temperature dependent transitions. X-ray diffraction analysis showed that lithium triflate forms a 1:1 aggregated solvate having 6 ion pair coordinated by 6 solvent molecules. Taken together, data suggest ion transport in electrolytes is influenced by solvation.